Display rack



FIG. 1 is a perspective view of a display rack;

FIG. 2 is a side view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof.

The broken lines depict portions of the article that form no part of the claimed design. 

CLAIM The ornamental design for a display rack, as shown and described. 